540 - Drug Delivery Systems - Exam Iv - Ocular Diseases

Front 1

What is macular degeneration and how does it effect vision?

Back 1

Damage to the retina causing blindness usually in the center of an individual's vision

Front 2

What is "wet" macular degeneration?

Back 2

Abnormal blood vessel growth causes detachment of the retina -- The more severe of the two forms

Front 3

What is "dry" macular degeneration?

Back 3

Cellular debris accumulates between the retina and choroid causing the retina to become detached

Front 4

How do you treat macular degeneration?

Back 4

Dry: Anti-oxidants
Wet: Intra-vitreal anti-VEGF

Front 5

What is diabetic retinopathy and how does it effect vision?

Back 5

Formation of new blood vessels in the back of the eye which then leak blood. This causes spots in an individuals visual field

Front 6

How do you treat diabetic retinopathy?

Back 6

Blood sugar control, laser treatment, surgery

Front 7

What is Retinitis pigmentosa and how does it effect vision?

Back 7

A genetic condition resulting in pigment clumps. Noted for presenting with "tunnel vision"

Front 8

What is macular edema and how does it effect vision?

Back 8

The macular thickens or swells causing central vision loss while preserving peripheral vision. It is the most common cause of central vision loss in diabetes.

Front 9

How do you treat macular edema?

Back 9

Steroids, laser treatment

Front 10

What are the barriers for ocular delivery?

Back 10

1) Corneal and pre-corneal factors
2) Sclera
3) Blood-retainal barriers

Front 11

What is the tissue composition of the sclera?

Back 11

Proteoglycans, collagen fibers

Front 12

What is the tissue composition of the choroid?

Back 12

Endothelial cells with leaky junctions

Front 13

What is the tissue composition of the retinal pigment epithelium?

Back 13

Epithelial cells with tight junctions

Front 14

Which ocular delivery barrier possess tight junctions?

Back 14

The retinal pigment epithelium

Front 15

Which ocular delivery barrier posses leaky junctions?

Back 15

The choroid

Front 16

How does the molecular radius of the drug effect drug permeability in the sclera?

Back 16

Exponential decrease with an increase in radius

Front 17

How does the molecular radius of the drug effect drug permeability in the choroid?

Back 17

Decrease with an increase in radius

Front 18

How does the molecular radius of the drug effect drug permeability in the retinal pigment epithelium?

Back 18

Exponential decrease with an increase in radius

Front 19

How does the lipophilicity of the drug molecular affect permeability in the sclera?

Back 19

Permeability decreases with increasing lipophilicity

Front 20

How does the lipophilicity of the drug molecular affect permeability in the choroid?

Back 20

Permeability decreases with increasing lipophilicity

Front 21

How does the lipophilicity of the drug molecular affect permeability in the retinal pigment epithelium?

Back 21

Permeability increases with increasing lipophilicity

Front 22

How does charge effect drug permeability in the sclera?

Back 22

Permeability increases with negatively charged solutes

Front 23

How does charge effect drug permeability in the choroid?

Back 23

Permeability increases with negatively charged solutes

Front 24

When are intraviteral injections used?

Back 24

For diabetic macular edema and wet age-related macular degeneration

Front 25

What are the advantages of intraviteral injections?

Back 25

1) Bypasses the blood-retinal barriers
2) Achieves high drug levels in the retina

Front 26

What are the disadvantages of intraviteral injections?

Back 26

1) Retinal Detachment
2) Endophthalmitis
3) Risk of glaucoma and cataract
4) Poor patient compliance
5) Drug is rapidly cleared by passive diffusion OR active secretion into the system circulation

Front 27

What are two types of ocular implants?

Back 27

Reservoir device (non-eroding)

Matrix device (Eroding and non-eroding)

Front 28

What are some facts pertaining to reservoir implant delivery systems

Back 28

1) Non-erodible
2) Complex to implant and remove
3) Offer more precise rate control than biodegradable systems

Front 29

What are some examples of reservoir systems?

Back 29

Vitrasert, Retisert, Iluvien

Front 30

Name facts pertaining to matrix implant delivery systems

Back 30

1) Rate control through drug dissolution and release, and by excipient erosion
2) Biodegradable implants (final uncontrollable "burst")
3) Trending toward smaller devices that can be injected rather than inserted

Front 31

What are some examples of matrix implant systems?

Back 31

Ozurdex (erodible), I-Vation (non-eroding)

Front 32

What are the advantages of liposomes and nanoparticles in ocular drug delivery?

Back 32

1) Increased stability and half life (decreased frequency of administration)
2) Eliminate "burst" in drug release (lower toxicity)
3) Localized drug delivery
4) Improved patient compliance

Front 33

What are the disadvantages of liposomes and nanoparticles in ocular drug delivery?

Back 33

1) Endophthalmitis
2) Retinal Detachment
3) Intraocular clouding

Front 34

What are the advantages of trans-scleral iontophoresis?

Back 34

1) Non-invasive
2) May be combined with other drug systems
3) Good drug penetration
4) Less risk of toxicity
5) Broad range of drugs can be used

Front 35

What are the disadvantages of trans-scleral iontophoresis?

Back 35

1) Repeated administrations -- Cannot sustain drug concentrations
2) Mild pain, retinal and chorodial burns
3) Limited data on efficacy in humans